Multi-dimensional cryptographically secured datastores for medical records

ABSTRACT

An example method comprises: performing a first intraoral scan of an oral cavity, the oral cavity including a dentition of a patient; identifying a first digital representation of dental anatomy associated with the dentition of the patient; causing the first digital representation of dental anatomy to be stored at an external storage location; appending, to a current data block of a main blockchain, a reference to a first data block of an auxiliary blockchain; appending, to the first data block of the auxiliary blockchain, an identifier of the external storage location; appending, to the current data block of the main blockchain, a first data item of the first digital representation of dental anatomy; appending, to the current data block of the main blockchain, a reference to a preceding data block of the main blockchain; and broadcasting the current data block of the main blockchain to a plurality of blockchain nodes.

RELATED APPLICATIONS

This patent application is a continuation of U.S. patent applicationSer. No. 16/676,194, filed Nov. 6, 2019, which claims the benefit under35 U.S.C. § 119(e) of U.S. Provisional Application No. 62/756,804, filedNov. 7, 2018, both of which are herein incorporated by reference.

TECHNICAL FIELD

The present disclosure is generally related to handling electronicdigital representations of patient anatomy by distributed computersystems and, in particular, to systems and methods implementingmulti-dimensional cryptographically-secured datastores for managingmedical records.

BACKGROUND

Medical treatment may involve evaluation of a medical condition,development and/or implementation of a treatment plan, coordination ofmedical resources, communication of healthcare needs to variousstakeholders (patients, next of kin, healthcare providers, insuranceentities, etc.), and/or evaluation of treatment results.

Medical treatment may be related to one or more treatment contexts,non-limiting examples of which include dental treatment (e.g.,prosthodontic or orthodontic treatment); orthopedic treatment for bone,spinal, etc. conditions (e.g., osteoporosis); treatment for hearing, earinfections, and/or other ear conditions; dialysis and/or otherprocedures for treatment of kidney disease and/or malfunction; etc.

Medical treatment plans may use a variety of techniques. As anillustrative example, a prosthodontic treatment plan may call formanufacture, installation, and use of dental prosthesis on a dental sitein a patient's oral cavity to treat gum disease, sleep apnea, and/orother intraoral conditions. An orthodontic treatment plan may usebrackets and wires, retainers, clear aligners, and/or functionalappliances to treat malocclusions and/or correct misalignment of apatient's dentition. In an illustrative example, an orthodontictreatment may be designed to move a patient's teeth to positions wherefunction and/or aesthetics are optimized. Traditionally, appliances suchas braces are applied to a patient's teeth by an orthodontist or dentistand the set of braces exerts continual force on the teeth and graduallyurges them toward their intended positions. Over time and with a seriesof clinical visits and adjustments to the braces, the orthodontistadjusts the appliances to move the teeth toward their final destination.Alternatives to conventional orthodontic treatment with traditionalaffixed appliances (e.g., braces) include systems including a series ofaligners. In these systems, multiple, and sometimes all, of the alignersto be worn by a patient may be designed and/or fabricated before thealigners are administered to a patient and/or reposition the patient'steeth (e.g., at the outset of treatment). The design and/or planning ofa customized treatment for a patient may make use of computer-basedthree-dimensional (3D) planning/design tools. The design of the alignerscan rely on computer modeling of a series of planned successive tootharrangements, and the individual aligners are designed to be worn overthe teeth and elastically reposition the teeth to each of the plannedtooth arrangements.

As additional examples of medical treatment plans, orthopedic treatmentplans may use surgical, interventional, minimally invasive, etc.procedures and/or medical devices to correct acute, degenerative, orother osteoporotic conditions. Other treatment plans may call formonitoring of medical conditions, corrective and/or other surgeries,application of medical devices (e.g., dialysis machines to performkidney dialysis), and intervention (periodic or otherwise) by medicalprofessionals.

A lot of digital data can be generated during the course of a medicaltreatment plan. Many dental treatment plans, for instance, call for apatient's dentition to be scanned at various points in time, includingduring initial/intermediate/final check-ups and/or at periodicintervals. These scans may include scans from an intraoral scanner or adigital representation of physical impressions captured at a treatmentlocation. Three-dimensional (3D) representations and/or two-dimensional(2D) images of a patient's smile, face, dental arches, etc. may bedeveloped/taken before, during and/or after dental treatment. Theserepresentations/images may show treatment progress for the patient, forexample. Dental, orthopedic, nephritic, aural, and/or other treatmentplans may generate video, images, anatomical renderings, notes,metadata, and other forms of digital data through the course oftreatment.

While it would be desirable to manage digital data related to a medicaltreatment plan, existing systems do not always make it efficient orconvenient to do so. For instance, many existing data management systemsare insufficiently secure, and/or are insufficiently accessible bypatients, healthcare providers, insurers, and/or other stakeholders.Many existing systems do not make it sufficiently convenient to leveragethe digital data generated during a medical treatment plan into avariety of platforms, including but not limited to those used for:diagnostics, progress tracking, claims verification with insurers and/orother arbitrage entities, and supply chain management.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is illustrated by way of example, and not by wayof limitation, in the figures of the accompanying drawings.

FIG. 1 schematically illustrates a high-level component diagram of anexample distributed medical record management system implemented inaccordance with one or more aspects of the present disclosure.

FIG. 2 schematically illustrates two-dimensional blockchain structuresfor storing medical records implemented in accordance with one or moreaspects of the present disclosure.

FIG. 3 schematically illustrates example block structures of the mainand auxiliary blockchains implemented in accordance with one or moreaspects of the present disclosure.

FIG. 4 schematically illustrates a high-level component diagram ofanother example distributed medical record management system implementedin accordance with one or more aspects of the present disclosure.

FIG. 5 schematically illustrates an example blockchain implementing aproof-of-work consensus protocol in accordance with one or more aspectsof the present disclosure.

FIG. 6 depicts a flow diagram of one illustrative example of a method ofstoring digital representations of dental anatomy utilizing thetwo-dimensional blockchain structure implemented in accordance with oneor more aspects of the present disclosure.

FIG. 7 depicts a flow diagram of one illustrative example of a method ofupdating the two-dimensional blockchain structure to reflect migrationof digital representations of dental anatomy to a new external storagelocation, in accordance with one or more aspects of the presentdisclosure.

FIG. 8 depicts a flow diagram of one illustrative example of a method800 of servicing digital representation of dental anatomy requests, inaccordance with one or more aspects of the present disclosure, inaccordance with one or more aspects of the present disclosure.

FIG. 9 illustrates a diagrammatic representation of a machine in theexample form of a computing device within which a set of instructions,for causing the machine to perform the methods described herein.

FIG. 10 illustrates a tooth repositioning appliance, in accordance withembodiments.

FIG. 11 illustrates a tooth repositioning system, in accordance withembodiments.

FIG. 12 illustrates a method of orthodontic treatment using a pluralityof appliances, in accordance with embodiments.

FIG. 13 illustrates a method for designing an orthodontic appliance, inaccordance with embodiments.

FIG. 14 illustrates a method for digitally planning an orthodontictreatment, in accordance with embodiments.

DETAILED DESCRIPTION

Discussed herein are systems and methods implementing multi-dimensionalblockchain structures for storing digital representations of medicalanatomy, such as digital representations of dental anatomy. The systemsand methods herein address fundamental technical problems related tomanaging digital data that is generated and/or managed during the courseof a medical treatment plan. The systems and methods herein usemulti-dimensional blockchains to store the digital representations ofmedical anatomy that are generated during the course of a medicaltreatment plan. As noted herein, the systems and methods describedherein allow various platforms (including those platforms related todiagnostics, progress tracking, claims verification with insurers and/orother arbitrage entities, and supply chain management) to leveragedigital representations of medical anatomy.

A “blockchain,” as used herein, may include a datastore of records(e.g., “blocks”) that are linked to one another using cryptography. Insome implementations, blocks of a blockchain may contain a cryptographicvalue (e.g., a cryptographic hash) of another block (e.g., of a previousblock). Each block may contain other information, such as timestamps orother identifying information, and transaction data. Transaction datamay be represented in a variety of formats, including as a hash (e.g., amerkle tree root hash). A blockchain may form a “distributed ledger”(e.g., a consensus of replicated, shared, and synchronized digital datageographically spread across multiple sites, countries, or institutions)that can record transactions between parties in a verifiable and/orpermanent way. In some implementations, the blockchains herein may bemanaged by a network (e.g., a peer-to-peer (P2P) network) thatcollectively adheres to a protocol for inter-node communication and/orvalidation of new blocks. Once recorded, the data in a block in ablockchain may be protected from retroactive alteration withoutalteration of subsequent blocks (which may require consensus of thenetwork).

A “digital representation of medical anatomy,” (used interchangeablywith “digital medical anatomy” and an “integrated medical record”), asused herein, may include a digital depiction or plurality of digitaldepictions of a patient's body and/or anatomy. A digital representationof medical anatomy, for instance, may include textual content (e.g.,physician notes, referrals, test procedure results, prescriptions,orders, etc.) and multimedia content (e.g., audio files, video files,and/or medical images, such as electrocardiograms, three-dimensional(3D) scans, etc.). A digital representation of medical anatomy mayinclude multimedia content items of medical records that is utilized invarious medical fields. For example, in cardiology, electrocardiogramimages or magnetic resonance images (MRI) may be utilized fordiagnostics; in orthopedics, computer tomography (CT) and/or MRI imagesmay be utilized for tracking the spine deterioration or the bonedensity; in nuclear medicine, CT and/or MRI images may be utilized fordiagnosis and monitoring of cancerous tumors; in dentistry and/ororthodontics, digital representations of dental anatomy, such asthree-dimensional (3D) intraoral scans or cone beam computer tomography(CBCT) images, may be utilized for planning implant surgery, designingtooth repositioning appliances, and/or various other applications.

A digital representation of medical anatomy may include an integratedonline patient record. It may further include meta data (liketraditional patient chart components such as progress notes, reports,medications, and orders) with multimedia patient data such as medicalimages, electrocardiograms, 3D scans, motion video and audio files. Adigital representation of medical anatomy may include references(hyperlinks, pointers, etc.) to multimedia that is not stored in thepatient's chart due to size or format limitations.

In the dental context, a digital representation of medical anatomy mayinclude a digital representation of dental anatomy. A “digitalrepresentation of dental anatomy” used interchangeably with “digitaldental anatomy,” as used herein, may include a digital depiction or aplurality of digital depictions of a patient's dentition. Examples ofdigital representation(s) of dental anatomy include: the depictions(images and/or renditions) from an intraoral scanner, a digitaldepiction of the results of a physical mold used to capture a patient'sdentition, a digital depiction of the results of a physical mold used toform an intraoral appliance, a three-dimensional (3D) image and/orrendering of a patient's dentition, etc. A digital representation ofdental anatomy may include textual content (e.g., physician notes,referrals, test procedure results, prescriptions, etc.) and multimediacontent (e.g., medical images, audio files, video files, etc.).

Digital representations of dental anatomy may be efficiently utilized,e.g., in orthodontics, dentistry (including restorative and cosmeticdentistry), prosthodontics, periodontics, or oral surgery. A digitalrepresentation of dental anatomy may include two-dimensional and/orthree-dimensional images and/or depictions of a patient'sdentition-acquired and/or utilized at various stage of treatmentincluding design, manufacturing, fitting, and/or adjustment oforthodontic aligners.

Digital representations of dental anatomy may include intraoral images,which may be acquired using an intraoral scanner. These intraoral imagesmay be used to generate three-dimensional virtual models of thepatient's dental arch. At different stages of dental treatment (such asorthodontic treatment), additional 3D virtual models of the patient'sdental arch may be generated. Virtual models may be used to model apatient's dentition through the course of a treatment plan. In someembodiments, virtual models, alone or in conjunction with one or moretransformations, may be used to model orthodontic aligners (e.g.,polymeric aligners) for various treatment stages of a treatment plan.Virtual models may be used to model orthodontic aligners (e.g.,polymeric aligners) for various treatment stages of a treatment plan.Various additional two-dimensional and/or three-dimensional images, suchas images of a patient's smile, face, dental arches, etc. may beacquired before, during and/or after the treatment, in order to performvarious tasks, such as provide a photographic simulation of an outcomeof a proposed treatment plan, track progress of a treatment plan,determining efficacy of appliances (e.g., tooth repositioningappliances) used to implement the treatment plan, etc.

As another example, a digital representation of dental anatomy mayinclude intraoral scans of a patient's dentition at various times,including at various times (before treatment, intermediate treatmentstages, after a final treatment stage, etc.) through the course of atreatment plan. A digital representation of dental anatomy may includemodels of estimated results of application of a treatment plan (orportion thereof) on a patient's dentition, such as a 3D model and/orimage of an estimated result of at least a portion of the treatmentplan. A digital representation of dental anatomy may include multipleportions, such that each portion may reflect a specific medical event(such as a patient visit, a diagnostic procedure and/or treatmentperformed, etc.). Intraoral images of a patient dentition may begenerated by using an intraoral scanner and/or camera. Intraoral imagesmay be used to generate a three-dimensional virtual model of thepatient's teeth and surrounding gingiva tissues. Variousthree-dimensional and/or two-dimensional representations of a patient'ssmile, face, dental arches, etc., may be acquired before, during and/orafter the treatment.

Tooth repositioning appliances (such as orthodontic aligners) and/ortooth repositioning systems (such as systems of orthodontic aligners)may be used to correct malocclusions to a patient's dentition. Examplesof such tooth repositioning appliances/systems are shown in FIGS. 10 and11 . Tooth repositioning appliances may be used as part of anorthodontic treatment plan, an example of which is described inconjunction with FIG. 12 . Many orthodontic treatment plans prescribetreatment by a series of orthodontic aligners, such that eachorthodontic aligner of the series would implement a specific stage of atreatment plan, and/or has unique properties (e.g., shape(s)) comparedto other orthodontic aligners in the series. Though the number oforthodontic aligners used to implement an orthodontic treatment plan mayvary, many cases can prescribe from several to several dozen (e.g.,50-60) stages. Each stage may be implemented by an orthodontic alignerspecifically configured, alone, or in combination with other structures(such as attachments) to implement force systems unique to that stage.Each stage may be modeled by a variety of techniques, including byintraoral and/or other images taken from an intraoral scanner, by adigital rendering of a physical mold of a patient's dentition, bymodeling the estimated results of a treatment plan (or portion thereof)on the patient's dentition, by taking images of a patient's dentitionwith a camera or a phone, etc. Each stage may have one or more digitalrepresentations of dental anatomy associated with it.

In some implementations, digital representation(s) of dental anatomy maybe stored in distributed databases implemented as blockchains, thusproviding immutability, consistency, and availability of the digitalrepresentations of dental anatomy while avoiding common pitfalls ofcentralized or hierarchical solutions. In some implementations, thedigital representation(s) of dental anatomy may be associated withspecific medical event (such as a patient visit, a diagnostic procedureand/or treatment performed, etc.).

In an illustrative example, a digital representation of dental anatomyportion, which may include one or more data items (e.g., multiple dataitems related to a single patient visit), may be stored as a singletransaction record in a blockchain.

A blockchain may implement an immutable (append-only) database in whichreplicas of each transaction record, grouped in transaction blocks, arestored by multiple nodes. The transaction records stored on theblockchain may be cryptographically protected, e.g., by digitalsignatures of the transaction initiating nodes. A consensus protocol maybe implemented for the blockchain for validating transaction records bya majority of nodes, in order to enforce the transaction recordimmutability, thus making the blockchain an append-only data structure.In an illustrative example, the blockchain may implement a proof-of-workconsensus protocol, which requires that a node, before broadcasting ablock of transaction records, compute a value of a cryptographic noncesuch that a certain hash function applied to the block would produce apre-determined result. The significant computational complexity of thisnonce computation operation makes it computationally infeasible for amajority of nodes to modify a previously issued transaction block. Invarious other illustrative examples, other consensus protocols may beemployed by systems and methods described herein.

In order to address pertinent security and privacy requirements, systemsand methods of the present disclosure may utilize private blockchains orpermissioned public blockchains, and may further encrypt the digitalrepresentation of dental anatomy data using secret cryptographic keys,as described in more detail herein below.

As noted herein above, a digital representation of dental anatomyportion, which may include one or more data items (e.g., multiple dataitems related to a single patient visit), may be stored as a singletransaction record in a blockchain. The size of a transaction block maybe pre-determined according to requirements of a particular blockchainimplementation. The block size would usually fall within the rangebetween several kilobytes and several megabytes (for example, theBitcoin network currently operates with 1 Mb blocks). The limited blocksize, which can be small in comparison to the size of a correspondingmultimedia content file (e.g., a three-dimensionalrendering/representation of a patient's dentition), may represent animpediment to utilizing blockchains for storing medical records whichinclude such images and/or other multimedia content.

Systems and methods described herein may effectively address the blocksize limitation by storing the multimedia content of a digitalrepresentation of dental anatomy on an external storage (such ascloud-based storage or any other network-accessible storage) rather thanon the blockchain itself. For instance, a blockchain could be employedfor storing the textual content of a digital representation of dentalanatomy and an identifier of the external storage location of themultimedia content of the digital representation of dental anatomy. Thisapproach preserves immutability, consistency, and availability ofmedical records while relieving a blockchain from the burden of storinglarge multimedia content files.

While the examples described herein are related to storing multimediacontent of digital representations of dental anatomy, the systems andmethods of the present disclosure may similarly enable utilizingmulti-dimensional blockchain structures for storing multimedia contentfor various other applications. In an illustrative example, themultimedia content may include digital models and/or images utilized for3D printing. In another illustrative example, the multimedia content mayinclude audiovisual content. In another illustrative example, themultimedia content may include digital models and/or images utilized forcomputer-aided design (CAD).

In some embodiments, it may be desirable to allow migration ofmultimedia content: the immutability of records stored in the blockchaininhibits modifications of the identifiers of the external storagelocations referenced by the blockchain records, even if a particularmultimedia content item has been migrated to another storage location.“Migration of multimedia content” herein shall refer to moving themultimedia content from a source external storage location to adestination external storage location, such that the two locations areaddressable by different location identifiers (e.g., Universal ResourceIdentifiers (URIs)). In an illustrative example, such migration may beperformed by transmitting the multimedia content over one or morenetworks from the source external storage location to the destinationexternal storage location. Such migration may be caused by variousreasons, e.g., data center consolidation, migration from a private datacenter to a public cloud, migration from one cloud service provider toanother cloud service provider, etc.

In order to allow migration of the multimedia content, the systems andmethods described herein employ a two-dimensional blockchain structure,in which the main blockchain is employed to store non-multimedia (e.g.,textual) content of medical records while multiple auxiliary blockchainsstore identifiers of external storage locations utilized for storing themultimedia content of the digital representations of dental anatomy.Accordingly, a typical block of the main blockchain, in addition tostoring non-multimedia portions of a digital representation of dentalanatomy, could include a reference to an associated auxiliary blockchainwhich stores identifiers of external storage locations utilized forstoring the multimedia content of the digital representations of dentalanatomy, as described in more detail herein below. The terms “mainblockchain” and “auxiliary blockchain” are used herein to designate twoblockchains. It is noted the terms “main” and “auxiliary” may, but neednot, impose a hierarchical or other relationship between the two typesof blockchains.

The systems and methods described herein may be efficiently utilized fortracking a patient's progress according to a planned treatment,incorporating enhanced tracking techniques into the treatment deliveryand management, and modifying the patient's treatment plan based on adetermination that treatment has progressed off track. Informationobtained according to the invention techniques can be used, for example,to more actively and/or effectively manage delivery of orthodontictreatment, increasing treatment efficacy and successful progression tothe patient's teeth to the desired finished positions.

Various aspects of the above-referenced methods and systems aredescribed in detail herein below by way of examples, rather than by wayof limitation. While specific examples described herein are related toorthodontic treatments, the systems and methods of the presentdisclosure may similarly be employed by in dentistry (includingprosthodontic (restorative and cosmetic) and orthodontic procedures),oral surgery, and/or various other medical areas in whichtwo-dimensional images, three-dimensional images and/or other multimediacontent of medical records may be utilized.

In various implementations of the systems and methods of the presentdisclosure, a distributed database for medical record management may beimplemented as a blockchain, the nodes of which may be maintained bypatient treatment facilities, health insurance providers, and/or otherrelevant parties, as schematically illustrated by FIG. 1 . As shown inFIG. 1 , the blockchain 100 may include multiple nodes 110A-110B whichstore copies of the digital representation of dental anatomy managementdatabase. Various client systems, such as patient devices (e.g.,smartphones) 120, supply chain systems 130, diagnostic tracking systems140, treatment plan tracking systems 150, and/or third party systems 160(such as health insurance providers) may access the database through thenetwork 170, which may include a combination of a wide area networks(such as the Internet) and local area networks.

FIG. 2 schematically illustrates an example two-dimensional blockchainstructure 200 which may be utilized by systems and methods describedherein. As shown in FIG. 2 , the example blockchain structure 200 mayinclude a main blockchain 210 and multiple auxiliary blockchains220A-220N, such that each auxiliary blockchain 220 is referenced by apointer stored by a respective block 230 of the main blockchain 220. Themain blockchain 220 may include a sequence of blocks 230A-230N which maybe employed for storing medical record data, except for the multimediacontent. In an illustrative example, the sequence of blocks 230A-230N ofthe main blockchain 220 may store medical record data items in thechronological order, such that the most recent event would be reflectedby the digital representation of dental anatomy data item stored by themost recently created block 230N of the main blockchain 220.

At least some of the blocks 230A-230N of the main blockchain mayreference respective auxiliary blockchains 220A-220N. An auxiliaryblockchain 220 including a sequence of blocks 240A-240Z may be employedfor storing identifiers of the locations of the external storage250A-250Z storing the associated multimedia content (e.g., medicalimages). In various illustrative examples, the external storage may beprovided by a cloud-based storage or any other type ofnetwork-accessible storage. The external storage may implement variousclustering, load balancing, and/or high availability features (e.g.,quorum-based clustering with weighted round-robin load balancing).

As schematically illustrated by FIG. 3 , an example block 230K of themain blockchain 220 stores one or more medical record data items260A-260N which are related to a single medical event (e.g., anoutpatient visit to a patient treatment facility). The digitalrepresentation of dental anatomy data items 260A-260N may includevarious textual and/or numerical content (e.g., physician notes,referrals, test or procedure results, prescriptions, wearable devicedata, etc.). The example block 230K of the main blockchain 220 mayfurther store a reference 270 (e.g., a pointer) to the leading block240A of the associated auxiliary blockchain 220K. Blocks of the mainblockchain 200 may further include various other fields, which areomitted from FIGS. 2-2 for clarity and conciseness.

As schematically illustrated by FIGS. 1-2 , the auxiliary blockchain220K referenced by the example block 230K of the main blockchain 210 mayinclude one or more blocks 240A-240Z employed for storing identifiers ofexternal storage locations storing the multimedia content associatedwith the block 230K of the main blockchain 210. Thus, when a new block(e.g., the example block 230K) of the main blockchain 210 is created forstoring one or more medical record data items 260A-260N, the associatedmultimedia content (e.g., one or more medical images) is stored in anexternal storage location 250A. An identifier of the external storagelocation 250A (e.g., in the form of Universal Resource Identifier (URL))is stored in a newly created block 240A of the auxiliary blockchain220K. Finally, a reference 270 (e.g., a pointer) to the block 240A ofthe auxiliary blockchain 220L is stored in the block 230K of the mainblockchain 220.

In order to enforce blockchain immutability, each block of the mainblockchain 220, including the example block 230K, may include acryptographic hash 280 of the previous block (e.g., the block 230J) ofthe main blockchain 220. Storing, in each block of the main blockchain220, a cryptographic hash of the previous block, in combination withother cryptographic protection features, make the blockchain immutable,as described in more detail herein below with references to FIG. 5 .

In various implementations of the systems and methods described herein,the multimedia content stored in the external storage may becryptographically encrypted in order to address pertinent security andprivacy concerns and/or regulations. In an illustrative example,referring again to FIG. 2 , a secret cryptographic key 190 utilized forcryptographically encrypting the multimedia content before storing themultimedia content in the external storage may be stored by theassociated block 230 of the main blockchain 220. In another illustrativeexample, the secret cryptographic key utilized for cryptographicallyencrypting the multimedia content may be stored by the associated block240 of the auxiliary blockchain 220.

Referring to FIG. 2 , if the multimedia content that has been initiallystored in the external storage location 250A is later migrated to a newexternal storage location 250B (which, in an illustrative example, maybe within the same or different private cloud or public cloud as thestorage location 250A), a new block 240B of the auxiliary blockchain220K is created. An identifier of the external storage location 250B(e.g., in the form of URL) is stored in the newly created block 240B ofthe auxiliary blockchain 220.

Similarly, as schematically illustrated by FIG. 3 , if the multimediacontent that has been stored in the external storage location 250B islater migrated to a new external storage location 250C (which, in anillustrative example, may be within the same or different private cloudor public cloud as the storage locations 250A and/or 250C), a new block240C of the auxiliary blockchain 220K is created. An identifier of theexternal storage location 250C (e.g., in the form of URL) is stored inthe newly created block 240C of the auxiliary blockchain 220K. Blocks ofthe auxiliary blockchain 220K may further include various other fields,which are not shown in FIG. 3 .

Referring again to FIG. 2 , retrieval of a specified medical recordportion (e.g., a digital representation of dental anatomy portionidentified by a specified patient identifier and a date) may involveidentifying, in the main blockchain 210, the block (e.g., the exampleblock 230K) which stores the requisite medical record portion. In anillustrative example, identifying the relevant block 230K may involvetraversing the main blockchain 210 starting from the initial block untilthe relevant block is found (e.g., the block storing the requisitemedical record portion identified by the specified patient identifierand the date). In another illustrative example, search for the relevantblock may be facilitated by an index associated with the main blockchain210, such that each index entry would map, for a given patient, a date(such as a date of outpatient visit to a patient treatment facility) toan identifier of a block of the main blockchain 210 which stores thedigital representation of dental anatomy portion pertinent to thespecified date.

Responsive to determining that the identified block 230K includes avalid reference to the leading block 240A of the corresponding auxiliaryblockchain 220K, the computer system implementing the digitalrepresentation of dental anatomy retrieval operation may traverse theauxiliary blockchain 220L starting from the initial block 240A.Traversal of the auxiliary blockchain may be performed until theterminal block 240Z is found, such that the auxiliary blockchain 220Kcontains no blocks following the identified terminal block 240Z. Asexplained herein above, the terminal block 240Z of the auxiliaryblockchain 220L would store the identifier (e.g., in the form of URL) ofthe external storage location 250Z of the multimedia content (e.g., oneor more medical images) associated with the digital representation ofdental anatomy portion stored by the block 230K of the main blockchain210.

Accordingly, in operation, newly created records may be broadcasted bythe initiator node (e.g., a patient treatment facility) and may bereceived by all currently active blockchain nodes. Each transactionrecord may be digitally signed by the initiator's private key, such thatother nodes would be able to validate the digital signature using thepublic key of the transaction initiator node.

In various implementations of the systems and methods of the presentdisclosure, nodes of the main blockchain may be maintained by patienttreatment facilities, health insurance providers, and/or other relevantparties. As schematically illustrated by FIG. 4 , a patient treatmentfacility may have a digital representation of dental anatomy managementsystem, which may include a digital representation of dental anatomymanagement server 410 implementing functions of a blockchain node 420Aof the main blockchain including multiple nodes 420A-420Z communicatingto each other via a network 430. In course of an outpatient visit to apatient treatment facility, a three-dimensional intraoral image of thepatient may be acquired. The patient treatment facility staff may employa digital representation of dental anatomy management client 440 (e.g.,a personal computer, a tablet, or a similar computing device) to causethe digital representation of dental anatomy management server 410 tocreate, in the main blockchain, a new block for storing the digitalrepresentation of dental anatomy portion associated with the outpatientvisit. The digital representation of dental anatomy management server410 may encrypt the newly acquired three-dimensional intraoral imageusing a secret cryptographic key, and may store the newly acquired imagein an external storage location (e.g., a cloud-based storage location).The digital representation of dental anatomy management server 410 maythen create a new auxiliary blockchain block for storing an identifierof the external storage location, as described in more detail hereinabove with references to FIGS. 2-3 .

In course of a subsequent patient visit to the patient treatmentfacility, the patient treatment facility staff may employ a digitalrepresentation of dental anatomy management client 440 (e.g., a personalcomputer, a tablet, or a similar computing device) to cause the digitalrepresentation of dental anatomy management server 410 to retrieve thepreviously saved image and display the image on the screen of thedigital representation of dental anatomy management client 440.Furthermore, in course of a subsequent patient visit to the patienttreatment facility, a new three-dimensional intraoral image may beacquired, and a corresponding record may be appended to the mainblockchain, as described in more detail herein above with references toFIGS. 2-3 .

In order to address pertinent security and privacy requirements, systemsand methods of the present disclosure may utilize private blockchains orpermissioned public blockchains. A private or permissioned blockchainmay be implemented by establishing access control procedures withrespect to the blockchain nodes, such that only authenticated andauthorized nodes would be able to receive the new block broadcastsand/or access blockchain records stored by one or more serversimplementing the nodes of the private blockchain. Furthermore, accesscontrol may be also implemented with respect to the public keys of theblockchain participants (which are needed to verify digital signaturesof the data blocks).

As noted herein above, a consensus protocol may be implemented for theblockchain for validating transaction records by a majority of nodes, inorder to enforce the transaction record immutability, thus making theblockchain an append-only data structure. In an illustrative example,the blockchain may implement a proof-of-work consensus protocol, whichrequires that a node, before broadcasting a block of transactionrecords, compute a value of a cryptographic nonce such that a certainhash function applied to the block would produce a pre-determined result(e.g., a pre-determined binary value), as schematically illustrated byFIG. 5 . The significant computational complexity of this noncecomputation operation makes it computationally infeasible for a majorityof nodes to modify a previously issued transaction block. In variousother illustrative examples, other consensus protocols may be employedby systems and methods described herein.

In operation, a blockchain node may assemble several data items510A-510Z into a block, and may perform one or more cryptographicoperations on the block to produce a cryptographically protected block520L. In order to enforce the blockchain immutability, each block of theblockchain, including the example block 520, includes a cryptographichash 540K of the previous block (e.g., the block 520K) of theblockchain.

In an illustrative example, cryptographically protecting a block mayinvolve incrementing a nonce field 530L comprised by the block until avalue of the nonce is found such that a cryptographic hash 540L of theblock would satisfy a pre-defined condition (e.g., comprise apre-determined number of leading zero bits). A cryptographic hash may berepresented by an irreversible function mapping a first bit sequence ofarbitrary size to a second bit sequence of a pre-determined size, suchthat two different bit sequences are unlikely to produce the same hashvalue. The computations performed in order to cryptographically protecta block may be referred to as “proof-of-work.” In various otherillustrative examples, other consensus protocols (such as“proof-of-stake”) may be employed by systems and methods describedherein. In the “proof-of-stake” protocol, each block is validated by ablockchain participant who can demonstrate ownership of at least a partof a certain pool of assets. In various modifications of the“proof-of-stake” protocol, a validator's “stake” may be diminished inresponse to detecting a false validation (i.e., validation of an invalidblock) performed by the validator.

Upon producing a cryptographically protected block 520L, the node maybroadcast the cryptographically protected block 520L to the peer nodesand save the node in the local persistent storage (e.g., a database).

As noted herein above, the systems and methods described herein may beefficiently utilized for tracking a patient's progress according to aplanned treatment, incorporating enhanced tracking techniques into thetreatment delivery and management, and modifying the patient's treatmentplan based on a determination that treatment has progressed off track.Information obtained according to the invention techniques can be used,for example, to more actively and/or effectively manage delivery oforthodontic treatment, increasing treatment efficacy and successfulprogression to the patient's teeth to the desired finished positions.

Thus, in one aspect, the systems and methods described herein may beemployed for identifying deviations from a patient treatment plan, whichmay involve, for example, receiving a digital representation of anactual arrangement of a patient's teeth in course of implementing anorthodontic treatment plan and comparing the actual arrangement to apre-determined planned arrangement to determine if the actualarrangement substantially deviates from the planned arrangement. Suchcomparison may involve determining one or more positional differencesbetween the actual and planned arrangements of at least some of thecorresponding teeth.

The systems and methods described herein may be further employed formanaging delivery and patient progression through an orthodontictreatment plan, which may involve, for example, providing an initialtreatment plan for a patient, providing a set of orthodontic appliancesto the patient, tracking progression of the patient's teeth along thetreatment path, comparing the actual arrangement with a plannedarrangement to determine if the actual arrangement of the teeth matchesa planned tooth arrangement, and generating a revised treatment planwhere it is determined that the actual tooth arrangement deviates fromthe planned tooth arrangement. In another example, a method can includereceiving a digital representation of an actual arrangement of apatient's teeth in course of implementing the orthodontic treatmentplan; comparing the actual arrangement to a digital model of a plannedarrangement, and generating a revised treatment plan. Additionally, asnoted herein, the systems and methods herein may be used fordiagnostics, claims verifications with an arbitrage entity, and/orsupply chain management.

FIG. 6 depicts a flow diagram of one illustrative example of a method ofstoring digital representations of dental anatomy utilizing thetwo-dimensional blockchain structure implemented in accordance with oneor more aspects of the present disclosure. Method 600 and/or each of itsindividual functions, routines, subroutines, or operations may beperformed by one or more processors of the computer system (e.g.,example computing device 900 of FIG. 9 ) executing the method. Invarious implementations, method 600 may be performed by a singleprocessing thread. Alternatively, method 600 may be performed by two ormore processing threads, each thread executing one or more individualfunctions, routines, subroutines, or operations of the method. In anillustrative example, the processing threads implementing method 600 maybe synchronized (e.g., using semaphores, critical sections, and/or otherthread synchronization mechanisms). Alternatively, the processingthreads implementing method 600 may be executed asynchronously withrespect to each other. Therefore, while FIG. 6 and the associateddescription lists the operations of method 600 in certain order, variousimplementations of the method may perform at least some of the describedoperations in parallel and/or in arbitrary selected orders.

At block 610, a computing device implementing the method may receive adigital representation of dental anatomy (e.g., by performing anintraoral scan of an oral cavity of a patient). In an illustrativeexample, the digital representation of dental anatomy may athree-dimensional intraoral representation of a patient's dentition, asdescribed in more detail herein above.

At block 620, the computing device may encrypt the digitalrepresentation of dental anatomy using a secret cryptographic key, asdescribed in more detail herein above. In an illustrative example, thesecret cryptographic key may be generated by a software-implementedmethod applying a key-generation function to an entropy source (e.g., arandom number generator). In another illustrative example, the secretcryptographic key may be generated by a hardware device, such as ahardware security module (HSM).

At block 630, the computing device may cause the encrypted digitalrepresentation of dental anatomy to be stored at an external storagelocation. In an illustrative example, the computing device may transmitthe encrypted digital representation of dental anatomy to a cloud-basedstorage server, as described in more detail herein above.

At block 640, the computing device may append, to the current data blockof the main blockchain utilized for storing the digital representationsof dental anatomy, a reference to the leading data block of an auxiliaryblockchain utilized for storing references to external storage locationsof the digital representations of dental anatomy multimedia content.

At block 650, the computing device may append, to the leading data blockof the auxiliary blockchain, an identifier of the external storagelocation (e.g., in the form of a URI) in which the digitalrepresentation of dental anatomy is stored.

At block 660, the computing device may append, to the current data blockof the main blockchain, one or more data items of the digitalrepresentation of dental anatomy. The data items may be utilized forstoring textual and/or numerical content associated with the digitalrepresentation of dental anatomy, which in various illustrative examplesmay include physician notes, referrals, test or procedure results,prescriptions, wearable device data, etc., as described in more detailherein above.

At block 670, the computing device may append, to the current data blockof the main blockchain, a data item storing the secret cryptographic keyutilized for encrypting the digital representation of dental anatomy, asdescribed in more detail herein above.

At block 680, the computing device may append, to the current data blockof the main blockchain, a reference to the preceding data block of themain blockchain. In an illustrative example, the reference to thepreceding data block may include a cryptographic hash of the previousblock, as described in more detail herein above.

At block 690, the computing device may broadcast the current data blockof the main blockchain to a plurality of blockchain nodes.

At block 695, the computing device may utilize the digitalrepresentation of the dental anatomy to generate instructions to managea treatment plan using the first digital representation of dentalanatomy.

FIG. 7 depicts a flow diagram of one illustrative example of a method ofupdating the two-dimensional blockchain structure to reflect migrationof digital representations of dental anatomy to a new external storagelocation, in accordance with one or more aspects of the presentdisclosure. Method 700 and/or each of its individual functions,routines, subroutines, or operations may be performed by one or moreprocessors of the computer system (e.g., example computing device 900 ofFIG. 9 ) executing the method. In some implementations, method 700 maybe performed by a single processing thread. Alternatively, method 700may be performed by two or more processing threads, each threadexecuting one or more individual functions, routines, subroutines, oroperations of the method. In an illustrative example, the processingthreads implementing method 700 may be synchronized (e.g., usingsemaphores, critical sections, and/or other thread synchronizationmechanisms). Alternatively, the processing threads implementing method700 may be executed asynchronously with respect to each other.Therefore, while FIG. 7 and the associated description lists theoperations of method 700 in certain order, various implementations ofthe method may perform at least some of the described operations inparallel and/or in arbitrary selected orders.

At block 710, a computing device implementing the method may receive anotification that a previously stored digital representation of dentalanatomy has been migrated to a new external storage location. Thenotification may include the patient identifier and the image identifier(e.g., the date of acquiring the image), as described in more detailherein above. In various illustrative examples, the notification may bereceived via a communication socket, via an application programminginterface (API) call, or via another suitable inter-processcommunication mechanism.

At block 720, the computing device may identify (e.g., using the patientidentifier and the image identifier) the auxiliary blockchain which isutilized for storing the external storage locations of the digitalrepresentations of dental anatomy.

At block 730, the computing device may create a new data block of theauxiliary blockchain.

At block 740, the computing device may store, in the newly created datablock, an identifier of the external storage location (e.g., in the formof a URI) in which the digital representation of dental anatomy isstored after migration.

At block 750, the computing device may append, to the newly created datablock of the auxiliary blockchain, a reference to the previous datablock of the auxiliary blockchain. In an illustrative example, thereference to the previous data block may include a cryptographic hash ofthe previous block, as described in more detail herein above.

At block 760, the computing device may broadcast the second data blockof the auxiliary blockchain to the plurality of blockchain nodes, andthe method may terminate.

FIG. 8 depicts a flow diagram of one illustrative example of a method800 of servicing digital representation of dental anatomy requests, inaccordance with one or more aspects of the present disclosure. Method800 and/or each of its individual functions, routines, subroutines, oroperations may be performed by one or more processors of the computersystem (e.g., example computing device 900 of FIG. 9 ) executing themethod. In some implementations, method 800 may be performed by a singleprocessing thread. Alternatively, method 800 may be performed by two ormore processing threads, each thread executing one or more individualfunctions, routines, subroutines, or operations of the method. In anillustrative example, the processing threads implementing method 800 maybe synchronized (e.g., using semaphores, critical sections, and/or otherthread synchronization mechanisms). Alternatively, the processingthreads implementing method 800 may be executed asynchronously withrespect to each other. Therefore, while FIG. 8 and the associateddescription lists the operations of method 800 in certain order, variousimplementations of the method may perform at least some of the describedoperations in parallel and/or in arbitrary selected orders.

At block 810, a computing device implementing the method may receive adigital representation of dental anatomy request specifying a digitalrepresentation of dental anatomy identifier (e.g., a patient identifierand a date of a medical event, such as a patient visit, a diagnosticprocedure and/or treatment performed, an intraoral scan acquired, etc.).In various illustrative examples, the digital representation of dentalanatomy request may be received via a communication socket, via anapplication programming interface (API) call, or via another suitableinter-process communication mechanism. The digital representation ofdental anatomy request may be initiated by a digital representation ofdental anatomy management client device, as described in more detailherein above.

At block 820, the computing device may identify, among a plurality ofdata blocks of the main blockchain, the data block which stores thedigital representation of dental anatomy data item identified by thedigital representation of dental anatomy identifier, as described inmore detail herein above.

At block 830, the computing device may identify the leading data blockof the auxiliary blockchain, such that the leading data block of theauxiliary blockchain is referenced by the previously identified datablock of the main blockchain, as described in more detail herein above.

Responsive to determining, at block 840, that the current data block ofthe auxiliary blockchain is the terminal block of the auxiliaryblockchain, the computing device may, at block 850, retrieving thedigital representation of dental anatomy from the external storagelocation referenced by the terminal data block of the auxiliaryblockchain; otherwise, at block 860, the computing device may retrievethe next data block of the auxiliary blockchain.

At block 870, the computing device may retrieve, from the previouslyidentified block of the main blockchain, the cryptographic key utilizedfor encrypting/decrypting the digital representation of dental anatomyassociated with the digital representation of dental anatomy, asdescribed in more detail herein above.

At block 880, the computing device may decrypt the retrieved digitalrepresentation of dental anatomy using the cryptographic key, asdescribed in more detail herein above.

At block 890, the computing device may transmit the digitalrepresentation of dental anatomy and one or more associated medicalrecord data items to the digital representation of dental anatomymanagement client device, and the method may terminate.

As noted herein above, while specific examples described herein arerelated to orthodontic treatments, the systems and methods of thepresent disclosure may similarly be employed by in dentistry (includingprosthodontic (restorative and cosmetic) and orthodontic procedures),oral surgery, and/or various other medical areas in whichtwo-dimensional images, three-dimensional images and/or other multimediacontent of medical records may be utilized.

FIG. 9 illustrates a diagrammatic representation of a machine in theexample form of a computing device 900 within which a set ofinstructions, for causing the machine to perform any one or more of themethodologies discussed herein (e.g., the methods of FIGS. 6-8 ). Insome embodiments, the machine may be part of a design station orcommunicatively coupled to the design station. In alternativeembodiments, the machine may be connected (e.g., networked) to othermachines in a Local Area Network (LAN), an intranet, an extranet, or theInternet. For example, the machine may be networked to the designstation and/or a rapid prototyping apparatus such as a 3D printer or SLAapparatus. The machine may operate in the capacity of a server or aclient machine in a client-server network environment, or as a peermachine in a peer-to-peer (or distributed) network environment. Themachine may be a personal computer (PC), a tablet computer, a set-topbox (STB), a Personal Digital Assistant (PDA), a cellular telephone, aweb appliance, a server, a network router, switch or bridge, or anymachine capable of executing a set of instructions (sequential orotherwise) that specify actions to be taken by that machine. Further,while only a single machine is illustrated, the term “machine” shallalso be taken to include any collection of machines (e.g., computers)that individually or jointly execute a set (or multiple sets) ofinstructions to perform any one or more of the methodologies discussedherein.

The example computing device 900 includes a processing device 902, amain memory 904 (e.g., read-only memory (ROM), flash memory, dynamicrandom access memory (DRAM) such as synchronous DRAM (SDRAM), etc.), astatic memory 906 (e.g., flash memory, static random access memory(SRAM), etc.), and a secondary memory (e.g., a data storage device 928),which communicate with each other via a bus 908.

Processing device 902 represents one or more general-purpose processorssuch as a microprocessor, central processing unit, or the like. Moreparticularly, the processing device 902 may be a complex instruction setcomputing (CISC) microprocessor, reduced instruction set computing(RISC) microprocessor, very long instruction word (VLIW) microprocessor,processor implementing other instruction sets, or processorsimplementing a combination of instruction sets. Processing device 902may also be one or more special-purpose processing devices such as anapplication specific integrated circuit (ASIC), a field programmablegate array (FPGA), a digital signal processor (DSP), network processor,or the like. Processing device 902 is configured to execute theprocessing logic (instructions 926) for performing operations and stepsdiscussed herein.

The computing device 900 may further include a network interface device922 for communicating with a network 964. The computing device 900 alsomay include a video display unit 910 (e.g., a liquid crystal display(LCD) or a cathode ray tube (CRT)), an alphanumeric input device 912(e.g., a keyboard), a cursor control device 99 (e.g., a mouse), and asignal generation device 920 (e.g., a speaker).

The data storage device 928 may include a machine-readable storagemedium (or more specifically a non-transitory computer-readable storagemedium) 924 on which is stored one or more sets of instructions 926embodying any one or more of the methodologies or functions describedherein. A non-transitory storage medium refers to a storage medium otherthan a carrier wave. The instructions 926 may also reside, completely orat least partially, within the main memory 904 and/or within theprocessing device 902 during execution thereof by the computer device900, the main memory 904 and the processing device 902 also constitutingcomputer-readable storage media.

The computer-readable storage medium 924 may also be used to store oneor more digital models of aligners and/or dental arches (also referredto as electronic models), medical data such as 2D and/or 3D images ofteeth, dental arches, smiles, etc. and/or an medical record managementmodule 950, which may perform one or more of the operations of themethods described herein. The computer readable storage medium 924 mayalso store a software library containing methods that call the digitalrepresentation of dental anatomy management 950. While thecomputer-readable storage medium 924 is shown in an example embodimentto be a single medium, the term “computer-readable storage medium”should be taken to include a single medium or multiple media (e.g., acentralized or distributed database, and/or associated caches andservers) that store the one or more sets of instructions. The term“computer-readable storage medium” shall also be taken to include anymedium that is capable of storing or encoding a set of instructions forexecution by the machine and that cause the machine to perform any oneor more of the methodologies of the present disclosure. The term“computer-readable storage medium” shall accordingly be taken toinclude, but not be limited to, solid-state memories, and optical andmagnetic media.

FIG. 10 illustrates an exemplary tooth repositioning appliance oraligner 1000 that can be worn by a patient in order to achieve anincremental repositioning of individual teeth 1002 in the jaw. Theappliance can include a shell (e.g., a continuous polymeric shell or asegmented shell) having teeth-receiving cavities that receive andresiliently reposition the teeth. An appliance or portion(s) thereof maybe indirectly fabricated using a physical model of teeth. For example,an appliance (e.g., polymeric appliance) can be formed using a physicalmodel of teeth and a sheet of suitable layers of polymeric material. A“polymeric material,” as used herein, may include any material formedfrom a polymer.

The aligner 1000 can fit over all teeth present in an upper or lowerjaw, or less than all of the teeth. The appliance can be designedspecifically to accommodate the teeth of the patient (e.g., thetopography of the tooth-receiving cavities matches the topography of thepatient's teeth), and may be fabricated based on positive or negativemodels of the patient's teeth generated by impression, scanning, and thelike. Alternatively, the appliance can be a generic appliance configuredto receive the teeth, but not necessarily shaped to match the topographyof the patient's teeth. In some cases, only certain teeth received by anappliance will be repositioned by the appliance while other teeth canprovide a base or anchor region for holding the appliance in place as itapplies force against the tooth or teeth targeted for repositioning. Insome cases, some, most, or even all of the teeth will be repositioned atsome point during treatment. Teeth that are moved can also serve as abase or anchor for holding the appliance as it is worn by the patient.Typically, no wires or other means will be provided for holding anappliance in place over the teeth. In some cases, however, it may bedesirable or necessary to provide individual attachments or otheranchoring elements 1004 on teeth 1002 with corresponding receptacles orapertures 1006 in the appliance 1000 so that the appliance can apply aselected force on the tooth. Exemplary appliances, including thoseutilized in the Invisalign® System, are described in numerous patentsand patent applications assigned to Align Technology, Inc. including,for example, in U.S. Pat. Nos. 6,450,807, and 5,975,893, as well as onthe company's website, which is accessible on the World Wide Web (see,e.g., the url “invisalign.com”). Examples of tooth-mounted attachmentssuitable for use with orthodontic appliances are also described inpatents and patent applications assigned to Align Technology, Inc.,including, for example, U.S. Pat. Nos. 6,309,210 and 6,830,450.

FIG. 11 illustrates a tooth repositioning system 1111 including aplurality of appliances 1112, 1114, 1116. Any of the appliancesdescribed herein can be designed and/or provided as part of a set of aplurality of appliances used in a tooth repositioning system. Eachappliance may be configured so a tooth-receiving cavity has a geometrycorresponding to an intermediate or final tooth arrangement intended forthe appliance. The patient's teeth can be progressively repositionedfrom an initial tooth arrangement to a target tooth arrangement byplacing a series of incremental position adjustment appliances over thepatient's teeth. For example, the tooth repositioning system 1111 caninclude a first appliance 1112 corresponding to an initial tootharrangement, one or more intermediate appliances 1114 corresponding toone or more intermediate arrangements, and a final appliance 1116corresponding to a target arrangement. A target tooth arrangement can bea planned final tooth arrangement selected for the patient's teeth atthe end of all planned dental (e.g., orthodontic) treatment.Alternatively, a target arrangement can be one of some intermediatearrangements for the patient's teeth during the course of the treatment,which may include various different treatment scenarios, including, butnot limited to, instances where surgery is recommended, whereinterproximal reduction (IPR) is appropriate, where a progress check isscheduled, where anchor placement is best, where palatal expansion isdesirable, where restorative dentistry is involved (e.g., inlays,onlays, crowns, bridges, implants, veneers, and the like), etc. As such,it is understood that a target tooth arrangement can be any plannedresulting arrangement for the patient's teeth that follows one or moreincremental repositioning stages. Likewise, an initial tooth arrangementcan be any initial arrangement for the patient's teeth that is followedby one or more incremental repositioning stages.

In some embodiments, the appliances 1112, 1114, 1116 (or portionsthereof) can be produced using indirect fabrication techniques, such asby thermoforming over a positive or negative mold. Indirect fabricationof an orthodontic appliance can involve producing a positive or negativemold of the patient's dentition in a target arrangement (e.g., by rapidprototyping, milling, etc.) and thermoforming one or more sheets ofmaterial over the mold in order to generate an appliance shell.

In an example of indirect fabrication, a mold of a patient's dental archmay be fabricated from a digital model of the dental arch, and a shellmay be formed over the mold (e.g., by thermoforming a polymeric sheetover the mold of the dental arch and then trimming the thermoformedpolymeric sheet). The fabrication of the mold may be performed by arapid prototyping machine (e.g., a stereolithography (SLA) 3D printer).The rapid prototyping machine may receive digital models of molds ofdental arches and/or digital models of the appliances 1112, 1114, 1116after the digital models of the appliances 1112, 1114, 1116 have beenprocessed by processing logic of a computing device, such as thecomputing device in FIG. 9 . The processing logic may include hardware(e.g., circuitry, dedicated logic, programmable logic, microcode, etc.),software (e.g., instructions executed by a processing device), firmware,or a combination thereof. For example, one or more operations may beperformed by a processing device executing an appliance design analysisprogram or module 1450.

To manufacture the molds, a shape of a dental arch for a patient at atreatment stage is determined based on a treatment plan. In the exampleof orthodontics, the treatment plan may be generated based on anintraoral scan of a dental arch to be modeled. The intraoral scan of thepatient's dental arch may be performed to generate a three dimensional(3D) virtual model of the patient's dental arch (mold). For example, afull scan of the mandibular and/or maxillary arches of a patient may beperformed to generate 3D virtual models thereof. The intraoral scan maybe performed by creating multiple overlapping intraoral images fromdifferent scanning stations and then stitching together the intraoralimages to provide a composite 3D virtual model. In other applications,virtual 3D models may also be generated based on scans of an object tobe modeled or based on use of computer aided drafting techniques (e.g.,to design the virtual 3D mold). Alternatively, an initial negative moldmay be generated from an actual object to be modeled (e.g., a dentalimpression or the like). The negative mold may then be scanned todetermine a shape of a positive mold that will be produced. An intraoralscan of a patient may be medical data that can be stored in a medicalrecord using a blockchain as described herein above. Additionally, oralternatively, one or more virtual 3D models may be medical data thatcan be stored in a medical record using a blockchain as described hereinabove.

Once the virtual 3D model of the patient's dental arch is generated, adental practitioner may determine a desired treatment outcome, whichincludes final positions and orientations for the patient's teeth.Processing logic may then determine a number of treatment stages tocause the teeth to progress from starting positions and orientations tothe target final positions and orientations. The shape of the finalvirtual 3D model and each intermediate virtual 3D model may bedetermined by computing the progression of tooth movement throughoutdental (e.g., orthodontic) treatment from initial tooth placement andorientation to final corrected tooth placement and orientation. For eachtreatment stage, a separate virtual 3D model of the patient's dentalarch at that treatment stage may be generated. The shape of each virtual3D model will be different. The original virtual 3D model, the finalvirtual 3D model and each intermediate virtual 3D model is unique andcustomized to the patient.

Accordingly, multiple different virtual 3D models (digital designs) of adental arch may be generated for a single patient. A first virtual 3Dmodel may be a unique model of a patient's dental arch and/or teeth asthey presently exist, and a final virtual 3D model may be a model of thepatient's dental arch and/or teeth after correction of one or more teethand/or a jaw. Multiple intermediate virtual 3D models may be modeled,each of which may be incrementally different from previous virtual 3Dmodels. Medical data that is stored in a medical record may include oneor more of the virtual 3D models.

Each virtual 3D model of a patient's dental arch may be used to generatea unique customized physical mold of the dental arch at a particularstage of treatment. The shape of the mold may be at least in part basedon the shape of the virtual 3D model for that treatment stage. Thevirtual 3D model may be represented in a file such as a computer aideddrafting (CAD) file or a 3D printable file such as a stereolithography(STL) file. The virtual 3D model for the mold may be sent to a thirdparty (e.g., clinician office, laboratory, manufacturing facility orother entity). The virtual 3D model may include instructions that willcontrol a fabrication system or device in order to produce the mold withspecified geometries.

A clinician office, laboratory, manufacturing facility or other entitymay receive the virtual 3D model of the mold, the digital model havingbeen created as set forth above. The entity may input the digital modelinto a rapid prototyping machine. The rapid prototyping machine thenmanufactures the mold using the digital model. One example of a rapidprototyping manufacturing machine is a 3D printer. 3D printing includesany layer-based additive manufacturing processes. 3D printing may beachieved using an additive process, where successive layers of materialare formed in proscribed shapes. 3D printing may be performed usingextrusion deposition, granular materials binding, lamination,photopolymerization, continuous liquid interface production (CLIP), orother techniques. 3D printing may also be achieved using a subtractiveprocess, such as milling.

In some instances, stereolithography (SLA), also known as opticalfabrication solid imaging, is used to fabricate an SLA mold. In SLA, themold is fabricated by successively printing thin layers of aphoto-curable material (e.g., a polymeric resin) on top of one another.A platform rests in a bath of a liquid photopolymer or resin just belowa surface of the bath. A light source (e.g., an ultraviolet laser)traces a pattern over the platform, curing the photopolymer where thelight source is directed, to form a first layer of the mold. Theplatform is lowered incrementally, and the light source traces a newpattern over the platform to form another layer of the mold at eachincrement. This process repeats until the mold is completely fabricated.Once all of the layers of the mold are formed, the mold may be cleanedand cured.

Materials such as a polyester, a co-polyester, a polycarbonate, apolycarbonate, a thermopolymeric polyurethane, a polypropylene, apolyethylene, a polypropylene and polyethylene copolymer, an acrylic, acyclic block copolymer, a polyetheretherketone, a polyamide, apolyethylene terephthalate, a polybutylene terephthalate, apolyetherimide, a polyethersulfone, a polytrimethylene terephthalate, astyrenic block copolymer (SBC), a silicone rubber, an elastomeric alloy,a thermopolymeric elastomer (TPE), a thermopolymeric vulcanizate (TPV)elastomer, a polyurethane elastomer, a block copolymer elastomer, apolyolefin blend elastomer, a thermopolymeric co-polyester elastomer, athermopolymeric polyamide elastomer, or combinations thereof, may beused to directly form the mold. The materials used for fabrication ofthe mold can be provided in an uncured form (e.g., as a liquid, resin,powder, etc.) and can be cured (e.g., by photopolymerization, lightcuring, gas curing, laser curing, crosslinking, etc.). The properties ofthe material before curing may differ from the properties of thematerial after curing.

Appliances may be formed from each mold and when applied to the teeth ofthe patient, may provide forces to move the patient's teeth as dictatedby the treatment plan. The shape of each appliance is unique andcustomized for a particular patient and a particular treatment stage. Inan example, the appliances 1112, 1114, 1116 can be pressure formed orthermoformed over the molds. Each mold may be used to fabricate anappliance that will apply forces to the patient's teeth at a particularstage of the treatment. The appliances 1112, 1114, 1116 each haveteeth-receiving cavities that receive and resiliently reposition theteeth in accordance with a particular treatment stage.

In one embodiment, a sheet of material is pressure formed orthermoformed over the mold. The sheet may be, for example, a sheet ofpolymeric (e.g., an elastic thermopolymeric, a sheet of polymericmaterial, etc.). To thermoform the shell over the mold, the sheet ofmaterial may be heated to a temperature at which the sheet becomespliable. Pressure may concurrently be applied to the sheet to form thenow pliable sheet around the mold. Once the sheet cools, it will have ashape that conforms to the mold. In one embodiment, a release agent(e.g., a non-stick material) is applied to the mold before forming theshell. This may facilitate later removal of the mold from the shell.Forces may be applied to lift the appliance from the mold. In someinstances, a breakage, warpage, or deformation may result from theremoval forces. Accordingly, embodiments disclosed herein may determinewhere the probable point or points of damage may occur in a digitaldesign of the appliance prior to manufacturing and may perform acorrective action.

Additional information may be added to the appliance. The additionalinformation may be any information that pertains to the appliance.Examples of such additional information includes a part numberidentifier, patient name, a patient identifier, a case number, asequence identifier (e.g., indicating which appliance a particular lineris in a treatment sequence), a date of manufacture, a clinician name, alogo and so forth. For example, after determining there is a probablepoint of damage in a digital design of an appliance, an indicator may beinserted into the digital design of the appliance. The indicator mayrepresent a recommended place to begin removing the polymeric applianceto prevent the point of damage from manifesting during removal in someembodiments. Such additional information may be included in a medicalrecord, which may be stored using blockchain techniques describedherein.

After an appliance is formed over a mold for a treatment stage, thatappliance is subsequently trimmed along a cutline (also referred to as atrim line) and the appliance may be removed from the mold. Theprocessing logic may determine a cutline for the appliance. Thedetermination of the cutline(s) may be made based on the virtual 3Dmodel of the dental arch at a particular treatment stage, based on avirtual 3D model of the appliance to be formed over the dental arch, ora combination of a virtual 3D model of the dental arch and a virtual 3Dmodel of the appliance. The location and shape of the cutline can beimportant to the functionality of the appliance (e.g., an ability of theappliance to apply desired forces to a patient's teeth) as well as thefit and comfort of the appliance. For shells such as orthodonticappliances, orthodontic retainers and orthodontic splints, the trimmingof the shell may play a role in the efficacy of the shell for itsintended purpose (e.g., aligning, retaining or positioning one or moreteeth of a patient) as well as the fit of the shell on a patient'sdental arch. For example, if too much of the shell is trimmed, then theshell may lose rigidity and an ability of the shell to exert force on apatient's teeth may be compromised. When too much of the shell istrimmed, the shell may become weaker at that location and may be a pointof damage when a patient removes the shell from their teeth or when theshell is removed from the mold. In some embodiments, the cut line may bemodified in the digital design of the appliance as one of the correctiveactions taken when a probable point of damage is determined to exist inthe digital design of the appliance.

On the other hand, if too little of the shell is trimmed, then portionsof the shell may impinge on a patient's gums and cause discomfort,swelling, and/or other dental issues. Additionally, if too little of theshell is trimmed at a location, then the shell may be too rigid at thatlocation. In some embodiments, the cutline may be a straight line acrossthe appliance at the gingival line, below the gingival line, or abovethe gingival line. In some embodiments, the cutline may be a gingivalcutline that represents an interface between an appliance and apatient's gingiva. In such embodiments, the cutline controls a distancebetween an edge of the appliance and a gum line or gingival surface of apatient.

Each patient has a unique dental arch with unique gingiva. Accordingly,the shape and position of the cutline may be unique and customized foreach patient and for each stage of treatment. For instance, the cutlineis customized to follow along the gum line (also referred to as thegingival line). In some embodiments, the cutline may be away from thegum line in some regions and on the gum line in other regions. Forexample, it may be desirable in some instances for the cutline to beaway from the gum line (e.g., not touching the gum) where the shell willtouch a tooth and on the gum line (e.g., touching the gum) in theinterproximal regions between teeth. Accordingly, it is important thatthe shell be trimmed along a predetermined cutline.

In some embodiments, the orthodontic appliances herein (or portionsthereof) can be produced using direct fabrication, such as additivemanufacturing techniques (also referred to herein as “3D printing) orsubtractive manufacturing techniques (e.g., milling). In someembodiments, direct fabrication involves forming an object (e.g., anorthodontic appliance or a portion thereof) without using a physicaltemplate (e.g., mold, mask etc.) to define the object geometry. Additivemanufacturing techniques can be categorized as follows: (1) vatphotopolymerization (e.g., stereolithography), in which an object isconstructed layer by layer from a vat of liquid photopolymer resin; (2)material jetting, in which material is jetted onto a build platformusing either a continuous or drop on demand (DOD) approach; (3) binderjetting, in which alternating layers of a build material (e.g., apowder-based material) and a binding material (e.g., a liquid binder)are deposited by a print head; (4) fused deposition modeling (FDM), inwhich material is drawn though a nozzle, heated, and deposited layer bylayer; (5) powder bed fusion, including but not limited to direct metallaser sintering (DMLS), electron beam melting (EBM), selective heatsintering (SHS), selective laser melting (SLM), and selective lasersintering (SLS); (6) sheet lamination, including but not limited tolaminated object manufacturing (LOM) and ultrasonic additivemanufacturing (UAM); and (7) directed energy deposition, including butnot limited to laser engineering net shaping, directed lightfabrication, direct metal deposition, and 3D laser cladding. Forexample, stereolithography can be used to directly fabricate one or moreof the appliances 1112, 1114, 1116. In some embodiments,stereolithography involves selective polymerization of a photosensitiveresin (e.g., a photopolymer) according to a desired cross-sectionalshape using light (e.g., ultraviolet light). The object geometry can bebuilt up in a layer-by-layer fashion by sequentially polymerizing aplurality of object cross-sections. As another example, the appliances1112, 1114, 1116 can be directly fabricated using selective lasersintering. In some embodiments, selective laser sintering involves usinga laser beam to selectively melt and fuse a layer of powdered materialaccording to a desired cross-sectional shape in order to build up theobject geometry. As yet another example, the appliances 1112, 1114, 1116can be directly fabricated by fused deposition modeling. In someembodiments, fused deposition modeling involves melting and selectivelydepositing a thin filament of thermoplastic polymer in a layer-by-layermanner in order to form an object. In yet another example, materialjetting can be used to directly fabricate the appliances 1112, 1114,1116. In some embodiments, material jetting involves jetting orextruding one or more materials onto a build surface in order to formsuccessive layers of the object geometry.

In some embodiments, the direct fabrication methods provided hereinbuild up the object geometry in a layer-by-layer fashion, withsuccessive layers being formed in discrete build steps. Alternatively orin combination, direct fabrication methods that allow for continuousbuild-up of an object geometry can be used, referred to herein as“continuous direct fabrication.” Various types of continuous directfabrication methods can be used. As an example, in some embodiments, theappliances 1112, 1114, 1116 are fabricated using “continuous liquidinterphase printing,” in which an object is continuously built up from areservoir of photopolymerizable resin by forming a gradient of partiallycured resin between the building surface of the object and apolymerization-inhibited “dead zone.” In some embodiments, asemi-permeable membrane is used to control transport of aphotopolymerization inhibitor (e.g., oxygen) into the dead zone in orderto form the polymerization gradient. Continuous liquid interphaseprinting can achieve fabrication speeds about 25 times to about 110times faster than other direct fabrication methods, and speeds about1100 times faster can be achieved with the incorporation of coolingsystems. Continuous liquid interphase printing is described in U.S.Patent Publication Nos. 2011/0097311, 2011/0097316, and 2011/0112532,the disclosures of each of which are incorporated herein by reference intheir entirety.

As another example, a continuous direct fabrication method can achievecontinuous build-up of an object geometry by continuous movement of thebuild platform (e.g., along the vertical or Z-direction) during theirradiation phase, such that the hardening depth of the irradiatedphotopolymer is controlled by the movement speed. Accordingly,continuous polymerization of material on the build surface can beachieved. Such methods are described in U.S. Pat. No. 7,892,474, thedisclosure of which is incorporated herein by reference in its entirety.

In another example, a continuous direct fabrication method can involveextruding a composite material composed of a curable liquid materialsurrounding a solid strand. The composite material can be extruded alonga continuous three-dimensional path in order to form the object. Suchmethods are described in U.S. Patent Publication No. 2014/0061974, thedisclosure of which is incorporated herein by reference in its entirety.

In yet another example, a continuous direct fabrication method utilizesa “heliolithography” approach in which the liquid photopolymer is curedwith focused radiation while the build platform is continuously rotatedand raised. Accordingly, the object geometry can be continuously builtup along a spiral build path. Such methods are described in U.S. PatentPublication No. 2014/0265034, the disclosure of which is incorporatedherein by reference in its entirety.

The direct fabrication approaches provided herein are compatible with awide variety of materials, including but not limited to one or more ofthe following: a polyester, a co-polyester, a polycarbonate, athermoplastic polyurethane, a polypropylene, a polyethylene, apolypropylene and polyethylene copolymer, an acrylic, a cyclic blockcopolymer, a polyetheretherketone, a polyamide, a polyethyleneterephthalate, a polybutylene terephthalate, a polyetherimide, apolyethersulfone, a polytrimethylene terephthalate, a styrenic blockcopolymer (SBC), a silicone rubber, an elastomeric alloy, athermoplastic elastomer (TPE), a thermoplastic vulcanizate (TPV)elastomer, a polyurethane elastomer, a block copolymer elastomer, apolyolefin blend elastomer, a thermoplastic co-polyester elastomer, athermoplastic polyamide elastomer, a thermoset material, or combinationsthereof. The materials used for direct fabrication can be provided in anuncured form (e.g., as a liquid, resin, powder, etc.) and can be cured(e.g., by photopolymerization, light curing, gas curing, laser curing,crosslinking, etc.) in order to form an orthodontic appliance or aportion thereof. The properties of the material before curing may differfrom the properties of the material after curing. Once cured, thematerials herein can exhibit sufficient strength, stiffness, durability,biocompatibility, etc. for use in an orthodontic appliance. Thepost-curing properties of the materials used can be selected accordingto the desired properties for the corresponding portions of theappliance.

In some embodiments, relatively rigid portions of the orthodonticappliance can be formed via direct fabrication using one or more of thefollowing materials: a polyester, a co-polyester, a polycarbonate, athermoplastic polyurethane, a polypropylene, a polyethylene, apolypropylene and polyethylene copolymer, an acrylic, a cyclic blockcopolymer, a polyetheretherketone, a polyamide, a polyethyleneterephthalate, a polybutylene terephthalate, a polyetherimide, apolyethersulfone, and/or a polytrimethylene terephthalate.

In some embodiments, relatively elastic portions of the orthodonticappliance can be formed via direct fabrication using one or more of thefollowing materials: a styrenic block copolymer (SBC), a siliconerubber, an elastomeric alloy, a thermoplastic elastomer (TPE), athermoplastic vulcanizate (TPV) elastomer, a polyurethane elastomer, ablock copolymer elastomer, a polyolefin blend elastomer, a thermoplasticco-polyester elastomer, and/or a thermoplastic polyamide elastomer.

Machine parameters can include curing parameters. For digital lightprocessing (DLP)-based curing systems, curing parameters can includepower, curing time, and/or grayscale of the full image. For laser-basedcuring systems, curing parameters can include power, speed, beam size,beam shape and/or power distribution of the beam. For printing systems,curing parameters can include material drop size, viscosity, and/orcuring power. These machine parameters can be monitored and adjusted ona regular basis (e.g., some parameters at every 1-x layers and someparameters after each build) as part of the process control on thefabrication machine. Process control can be achieved by including asensor on the machine that measures power and other beam parametersevery layer or every few seconds and automatically adjusts them with afeedback loop. For DLP machines, gray scale can be measured andcalibrated before, during, and/or at the end of each build, and/or atpredetermined time intervals (e.g., every n^(th) build, once per hour,once per day, once per week, etc.), depending on the stability of thesystem. In addition, material properties and/or photo-characteristicscan be provided to the fabrication machine, and a machine processcontrol module can use these parameters to adjust machine parameters(e.g., power, time, gray scale, etc.) to compensate for variability inmaterial properties. By implementing process controls for thefabrication machine, reduced variability in appliance accuracy andresidual stress can be achieved.

Optionally, the direct fabrication methods described herein allow forfabrication of an appliance including multiple materials, referred toherein as “multi-material direct fabrication.” In some embodiments, amulti-material direct fabrication method involves concurrently formingan object from multiple materials in a single manufacturing step. Forinstance, a multi-tip extrusion apparatus can be used to selectivelydispense multiple types of materials from distinct material supplysources in order to fabricate an object from a plurality of differentmaterials. Such methods are described in U.S. Pat. No. 6,749,414, thedisclosure of which is incorporated herein by reference in its entirety.Alternatively or in combination, a multi-material direct fabricationmethod can involve forming an object from multiple materials in aplurality of sequential manufacturing steps. For instance, a firstportion of the object can be formed from a first material in accordancewith any of the direct fabrication methods herein, then a second portionof the object can be formed from a second material in accordance withmethods herein, and so on, until the entirety of the object has beenformed.

Direct fabrication can provide various advantages compared to othermanufacturing approaches. For instance, in contrast to indirectfabrication, direct fabrication permits production of an orthodonticappliance without utilizing any molds or templates for shaping theappliance, thus reducing the number of manufacturing steps involved andimproving the resolution and accuracy of the final appliance geometry.Additionally, direct fabrication permits precise control over thethree-dimensional geometry of the appliance, such as the appliancethickness. Complex structures and/or auxiliary components can be formedintegrally as a single piece with the appliance shell in a singlemanufacturing step, rather than being added to the shell in a separatemanufacturing step. In some embodiments, direct fabrication is used toproduce appliance geometries that would be difficult to create usingalternative manufacturing techniques, such as appliances with very smallor fine features, complex geometric shapes, undercuts, interproximalstructures, shells with variable thicknesses, and/or internal structures(e.g., for improving strength with reduced weight and material usage).For example, in some embodiments, the direct fabrication approachesherein permit fabrication of an orthodontic appliance with feature sizesof less than or equal to about 5 μm, or within a range from about 5 μmto about 50 μm, or within a range from about 20 μm to about 50 μm.

The direct fabrication techniques described herein can be used toproduce appliances with substantially isotropic material properties,e.g., substantially the same or similar strengths along all directions.In some embodiments, the direct fabrication approaches herein permitproduction of an orthodontic appliance with a strength that varies by nomore than about 25%, about 20%, about 11%, about 11%, about 5%, about1%, or about 0.5% along all directions. Additionally, the directfabrication approaches herein can be used to produce orthodonticappliances at a faster speed compared to other manufacturing techniques.In some embodiments, the direct fabrication approaches herein allow forproduction of an orthodontic appliance in a time interval less than orequal to about 1 hour, about 30 minutes, about 25 minutes, about 20minutes, about 11 minutes, about 11 minutes, about 5 minutes, about 4minutes, about 3 minutes, about 2 minutes, about 1 minutes, or about 30seconds. Such manufacturing speeds allow for rapid “chair-side”production of customized appliances, e.g., during a routine appointmentor checkup.

In some embodiments, the direct fabrication methods described hereinimplement process controls for various machine parameters of a directfabrication system or device in order to ensure that the resultantappliances are fabricated with a high degree of precision. Suchprecision can be beneficial for ensuring accurate delivery of a desiredforce system to the teeth in order to effectively elicit toothmovements. Process controls can be implemented to account for processvariability arising from multiple sources, such as the materialproperties, machine parameters, environmental variables, and/orpost-processing parameters.

Material properties may vary depending on the properties of rawmaterials, purity of raw materials, and/or process variables duringmixing of the raw materials. In many embodiments, resins or othermaterials for direct fabrication should be manufactured with tightprocess control to ensure little variability in photo-characteristics,material properties (e.g., viscosity, surface tension), physicalproperties (e.g., modulus, strength, elongation) and/or thermalproperties (e.g., glass transition temperature, heat deflectiontemperature). Process control for a material manufacturing process canbe achieved with screening of raw materials for physical propertiesand/or control of temperature, humidity, and/or other process parametersduring the mixing process. By implementing process controls for thematerial manufacturing procedure, reduced variability of processparameters and more uniform material properties for each batch ofmaterial can be achieved. Residual variability in material propertiescan be compensated with process control on the machine, as discussedfurther herein.

Machine parameters can include curing parameters. For digital lightprocessing (DLP)-based curing systems, curing parameters can includepower, curing time, and/or grayscale of the full image. For laser-basedcuring systems, curing parameters can include power, speed, beam size,beam shape and/or power distribution of the beam. For printing systems,curing parameters can include material drop size, viscosity, and/orcuring power. These machine parameters can be monitored and adjusted ona regular basis (e.g., some parameters at every 1-x layers and someparameters after each build) as part of the process control on thefabrication machine. Process control can be achieved by including asensor on the machine that measures power and other beam parametersevery layer or every few seconds and automatically adjusts them with afeedback loop. For DLP machines, gray scale can be measured andcalibrated at the end of each build. In addition, material propertiesand/or photo-characteristics can be provided to the fabrication machine,and a machine process control module can use these parameters to adjustmachine parameters (e.g., power, time, gray scale, etc.) to compensatefor variability in material properties. By implementing process controlsfor the fabrication machine, reduced variability in appliance accuracyand residual stress can be achieved.

In many embodiments, environmental variables (e.g., temperature,humidity, Sunlight or exposure to other energy/curing source) aremaintained in a tight range to reduce variable in appliance thicknessand/or other properties. Optionally, machine parameters can be adjustedto compensate for environmental variables.

In many embodiments, post-processing of appliances includes cleaning,post-curing, and/or support removal processes. Relevant post-processingparameters can include purity of cleaning agent, cleaning pressureand/or temperature, cleaning time, post-curing energy and/or time,and/or consistency of support removal process. These parameters can bemeasured and adjusted as part of a process control scheme. In addition,appliance physical properties can be varied by modifying thepost-processing parameters. Adjusting post-processing machine parameterscan provide another way to compensate for variability in materialproperties and/or machine properties.

The configuration of the orthodontic appliances herein can be determinedaccording to a treatment plan for a patient, e.g., a treatment planinvolving successive administration of a plurality of appliances forincrementally repositioning teeth. Computer-based treatment planningand/or appliance manufacturing methods can be used in order tofacilitate the design and fabrication of appliances. For instance, oneor more of the appliance components described herein can be digitallydesigned and fabricated with the aid of computer-controlledmanufacturing devices (e.g., computer numerical control (CNC) milling,computer-controlled rapid prototyping such as 3D printing, etc.). Thecomputer-based methods presented herein can improve the accuracy,flexibility, and convenience of appliance fabrication.

FIG. 12 illustrates a method 1250 of orthodontic treatment using aplurality of appliances, in accordance with embodiments. The method 1250can be practiced using any of the appliances or appliance sets describedherein. In block 1260, a first orthodontic appliance is applied to apatient's teeth in order to reposition the teeth from a first tootharrangement to a second tooth arrangement. In block 1270, a secondorthodontic appliance is applied to the patient's teeth in order toreposition the teeth from the second tooth arrangement to a third tootharrangement. The method 1250 can be repeated as necessary using anysuitable number and combination of sequential appliances in order toincrementally reposition the patient's teeth from an initial arrangementto a target arrangement. The appliances can be generated all at the samestage or in sets or batches (e.g., at the beginning of a stage of thetreatment), or the appliances can be fabricated one at a time, and thepatient can wear each appliance until the pressure of each appliance onthe teeth can no longer be felt or until the maximum amount of expressedtooth movement for that given stage has been achieved. A plurality ofdifferent appliances (e.g., a set) can be designed and even fabricatedprior to the patient wearing any appliance of the plurality. Afterwearing an appliance for an appropriate period of time, the patient canreplace the current appliance with the next appliance in the seriesuntil no more appliances remain. The appliances are generally notaffixed to the teeth and the patient may place and replace theappliances at any time during the procedure (e.g., patient-removableappliances). The final appliance or several appliances in the series mayhave a geometry or geometries selected to overcorrect the tootharrangement. For instance, one or more appliances may have a geometrythat would (if fully achieved) move individual teeth beyond the tootharrangement that has been selected as the “final.” Such over-correctionmay be desirable in order to offset potential relapse after therepositioning method has been terminated (e.g., permit movement ofindividual teeth back toward their pre-corrected positions).Over-correction may also be beneficial to speed the rate of correction(e.g., an appliance with a geometry that is positioned beyond a desiredintermediate or final position may shift the individual teeth toward theposition at a greater rate). In such cases, the use of an appliance canbe terminated before the teeth reach the positions defined by theappliance. Furthermore, over-correction may be deliberately applied inorder to compensate for any inaccuracies or limitations of theappliance. Images may be taken of a patient's smile during differentstages of orthodontic treatment (e.g., after one or more appliances havebeen worn). Such images may be stored in a patient medical record usingthe blockchain techniques described herein above.

FIG. 13 illustrates a method 1300 for designing an orthodontic applianceto be produced by direct fabrication, in accordance with embodiments.The method 1300 can be applied to any embodiment of the orthodonticappliances described herein. Some or all of the blocks of the method1300 can be performed by any suitable data processing system or device,e.g., one or more processors configured with suitable instructions.

In block 1310, a movement path to move one or more teeth from an initialarrangement to a target arrangement is determined. The initialarrangement can be determined from a mold or a scan of the patient'steeth or mouth tissue, e.g., using wax bites, direct contact scanning,x-ray imaging, tomographic imaging, sonographic imaging, and othertechniques for obtaining information about the position and structure ofthe teeth, jaws, gums and other orthodontically relevant tissue. Fromthe obtained data, a digital data set can be derived that represents theinitial (e.g., pretreatment) arrangement of the patient's teeth andother tissues. Optionally, the initial digital data set is processed tosegment the tissue constituents from each other. For example, datastructures that digitally represent individual tooth crowns can beproduced. Advantageously, digital models of entire teeth can beproduced, including measured or extrapolated hidden surfaces and rootstructures, as well as surrounding bone and soft tissue.

The target arrangement of the teeth (e.g., a desired and intended endresult of orthodontic treatment) can be received from a clinician in theform of a prescription, can be calculated from basic orthodonticprinciples, and/or can be extrapolated computationally from a clinicalprescription. With a specification of the desired final positions of theteeth and a digital representation of the teeth themselves, the finalposition and surface geometry of each tooth can be specified to form acomplete model of the tooth arrangement at the desired end of treatment.

Having both an initial position and a target position for each tooth, amovement path can be defined for the motion of each tooth. In someembodiments, the movement paths are configured to move the teeth in thequickest fashion with the least amount of round-tripping to bring theteeth from their initial positions to their desired target positions.The tooth paths can optionally be segmented, and the segments can becalculated so that each tooth's motion within a segment stays withinthreshold limits of linear and rotational translation. In this way, theend points of each path segment can constitute a clinically viablerepositioning, and the aggregate of segment end points can constitute aclinically viable sequence of tooth positions, so that moving from onepoint to the next in the sequence does not result in a collision ofteeth.

In block 1320, a force system to produce movement of the one or moreteeth along the movement path is determined. A force system can includeone or more forces and/or one or more torques. Different force systemscan result in different types of tooth movement, such as tipping,translation, rotation, extrusion, intrusion, root movement, etc.Biomechanical principles, modeling techniques, forcecalculation/measurement techniques, and the like, including knowledgeand approaches commonly used in orthodontia, may be used to determinethe appropriate force system to be applied to the tooth to accomplishthe tooth movement. In determining the force system to be applied,sources may be considered including literature, force systems determinedby experimentation or virtual modeling, computer-based modeling,clinical experience, minimization of unwanted forces, etc.

The determination of the force system can include constraints on theallowable forces, such as allowable directions and magnitudes, as wellas desired motions to be brought about by the applied forces. Forexample, in fabricating palatal expanders, different movement strategiesmay be desired for different patients. For example, the amount of forceneeded to separate the palate can depend on the age of the patient, asvery young patients may not have a fully-formed suture. Thus, injuvenile patients and others without fully-closed palatal sutures,palatal expansion can be accomplished with lower force magnitudes.Slower palatal movement can also aid in growing bone to fill theexpanding suture. For other patients, a more rapid expansion may bedesired, which can be achieved by applying larger forces. Theserequirements can be incorporated as needed to choose the structure andmaterials of appliances; for example, by choosing palatal expanderscapable of applying large forces for rupturing the palatal suture and/orcausing rapid expansion of the palate. Subsequent appliance stages canbe designed to apply different amounts of force, such as first applyinga large force to break the suture, and then applying smaller forces tokeep the suture separated or gradually expand the palate and/or arch.

The determination of the force system can also include modeling of thefacial structure of the patient, such as the skeletal structure of thejaw and palate. Scan data of the palate and arch, such as X-ray data or3D optical scanning data, for example, can be used to determineparameters of the skeletal and muscular system of the patient's mouth,so as to determine forces sufficient to provide a desired expansion ofthe palate and/or arch. Such data may be included in a digitalrepresentation of dental anatomy of a patient, which may be stored inaccordance with embodiments discussed herein. In some embodiments, thethickness and/or density of the mid-palatal suture may be measured, orinput by a treating professional. In other embodiments, the treatingprofessional can select an appropriate treatment based on physiologicalcharacteristics of the patient. For example, the properties of thepalate may also be estimated based on factors such as the patient'sage—for example, young juvenile patients will typically require lowerforces to expand the suture than older patients, as the suture has notyet fully formed.

In block 1330, an arch or palate expander design for an orthodonticappliance configured to produce the force system is determined.Determination of the arch or palate expander design, appliance geometry,material composition, and/or properties can be performed using atreatment or force application simulation environment. A simulationenvironment can include, e.g., computer modeling systems, biomechanicalsystems or apparatus, and the like. Optionally, digital models of theappliance and/or teeth can be produced, such as finite element models.The finite element models can be created using computer programapplication software available from a variety of vendors. For creatingsolid geometry models, computer aided engineering (CAE) or computeraided design (CAD) programs can be used, such as the AutoCAD® softwareproducts available from Autodesk, Inc., of San Rafael, Calif. Forcreating finite element models and analyzing them, program products froma number of vendors can be used, including finite element analysispackages from ANSYS, Inc., of Canonsburg, Pa., and SIMULIA (Abaqus)software products from Dassault Systèmes of Waltham, Mass.

Optionally, one or more arch or palate expander designs can be selectedfor testing or force modeling. As noted above, a desired tooth movement,as well as a force system required or desired for eliciting the desiredtooth movement, can be identified. Using the simulation environment, acandidate arch or palate expander design can be analyzed or modeled fordetermination of an actual force system resulting from use of thecandidate appliance. One or more modifications can optionally be made toa candidate appliance, and force modeling can be further analyzed asdescribed, e.g., in order to iteratively determine an appliance designthat produces the desired force system.

In block 1340, instructions for fabrication of the orthodontic applianceincorporating the arch or palate expander design are generated. Theinstructions can be configured to control a fabrication system or devicein order to produce the orthodontic appliance with the specified arch orpalate expander design. In some embodiments, the instructions areconfigured for manufacturing the orthodontic appliance using directfabrication (e.g., stereolithography, selective laser sintering, fuseddeposition modeling, 3D printing, continuous direct fabrication,multi-material direct fabrication, etc.), in accordance with the variousmethods presented herein. In alternative embodiments, the instructionscan be configured for indirect fabrication of the appliance, e.g., bythermoforming.

Method 1300 may comprise additional blocks: 1) The upper arch and palateof the patient is scanned intraorally to generate three dimensional dataof the palate and upper arch; 2) The three dimensional shape profile ofthe appliance is determined to provide a gap and teeth engagementstructures as described herein.

Although the above blocks show a method 1300 of designing an orthodonticappliance in accordance with some embodiments, a person of ordinaryskill in the art will recognize some variations based on the teachingdescribed herein. Some of the blocks may comprise sub-blocks. Some ofthe blocks may be repeated as often as desired. One or more blocks ofthe method 1300 may be performed with any suitable fabrication system ordevice, such as the embodiments described herein. Some of the blocks maybe optional, and the order of the blocks can be varied as desired.

FIG. 14 illustrates a method 1400 for digitally planning an orthodontictreatment and/or design or fabrication of an appliance, in accordancewith embodiments. The method 1400 can be applied to any of the treatmentprocedures described herein and can be performed by any suitable dataprocessing system.

In block 1410, a digital representation of a patient's teeth isreceived. The digital representation can include surface topography datafor the patient's intraoral cavity (including teeth, gingival tissues,etc.). The surface topography data can be generated by directly scanningthe intraoral cavity, a physical model (positive or negative) of theintraoral cavity, or an impression of the intraoral cavity, using asuitable scanning device (e.g., a handheld scanner, desktop scanner,etc.). The digital representation may be stored in a patient medicalrecord in accordance with embodiments described herein.

In block 1420, one or more treatment stages are generated based on thedigital representation of the teeth. The treatment stages can beincremental repositioning stages of an orthodontic treatment proceduredesigned to move one or more of the patient's teeth from an initialtooth arrangement to a target arrangement. For example, the treatmentstages can be generated by determining the initial tooth arrangementindicated by the digital representation, determining a target tootharrangement, and determining movement paths of one or more teeth in theinitial arrangement necessary to achieve the target tooth arrangement.The movement path can be optimized based on minimizing the totaldistance moved, preventing collisions between teeth, avoiding toothmovements that are more difficult to achieve, or any other suitablecriteria.

In block 1430, at least one orthodontic appliance is fabricated based onthe generated treatment stages. For example, a set of appliances can befabricated, each shaped according a tooth arrangement specified by oneof the treatment stages, such that the appliances can be sequentiallyworn by the patient to incrementally reposition the teeth from theinitial arrangement to the target arrangement. The appliance set mayinclude one or more of the orthodontic appliances described herein. Thefabrication of the appliance may involve creating a digital model of theappliance to be used as input to a computer-controlled fabricationsystem. The appliance can be formed using direct fabrication methods,indirect fabrication methods, or combinations thereof, as desired.

In some instances, staging of various arrangements or treatment stagesmay not be necessary for design and/or fabrication of an appliance. Asillustrated by the dashed line in FIG. 14 , design and/or fabrication ofan orthodontic appliance, and perhaps a particular orthodontictreatment, may include use of a representation of the patient's teeth(e.g., receive a digital representation of the patient's teeth 1410),followed by design and/or fabrication of an orthodontic appliance basedon a representation of the patient's teeth in the arrangementrepresented by the received representation.

In some implementations, fabrication instructions to fabricate amodified polymeric aligner based on the third digital model may beprovided. In some implementations, the fabrication instructions mayinclude: mold formation instructions to form a physical aligner mold forthe polymeric aligner using the third digital model; and/orthermoforming instructions to thermoform the polymeric aligner from asheet of polymeric material placed over the physical aligner mold. Asnoted herein, the third digital model may include one or more structuralfeatures at points relative to corresponding points of the seconddigital model, the one or more structural features being configured toaccommodate the one or more corrective actions. In variousimplementations, the fabrication instructions comprise directfabrication instructions to directly fabricate the polymeric alignerusing the third digital model. As noted herein, the third digital modelmay include one or more areas of modified thickness relative tocorresponding areas of the second digital model, the one or more areasof modified thickness being configured to accommodate the one or morecorrective actions

It is to be understood that the above description is intended to beillustrative, and not restrictive. Many other embodiments will beapparent upon reading and understanding the above description. Althoughembodiments of the present disclosure have been described with referenceto specific example embodiments, it will be recognized that thedisclosure is not limited to the embodiments described, but can bepracticed with modification and alteration within the spirit and scopeof the appended claims. Accordingly, the specification and drawings areto be regarded in an illustrative sense rather than a restrictive sense.The scope of the disclosure should, therefore, be determined withreference to the appended claims, along with the full scope ofequivalents to which such claims are entitled.

What is claimed is:
 1. A method comprising: performing a first intraoralscan of an oral cavity of a patient, the oral cavity including adentition of the patient; identifying a first digital representation ofdental anatomy associated with the dentition of the patient; encrypting,using a secret cryptographic key, the first digital representation ofdental anatomy; causing the encrypted first digital representation ofdental anatomy to be stored at a first external storage location;appending, to a current data block of a main blockchain, a reference toa first data block of an auxiliary blockchain; appending, to the currentdata block of the main blockchain, the secret cryptographic key;appending, to the first data block of the auxiliary blockchain, anidentifier of the first external storage location; appending, to thecurrent data block of the main blockchain, a first data item of thefirst digital representation of dental anatomy; appending, to thecurrent data block of the main blockchain, a reference to a precedingdata block of the main blockchain; broadcasting the current data blockof the main blockchain to a plurality of blockchain nodes; receiving anotification of migration of the encrypted first digital representationof dental anatomy to a second external storage location; creating asecond data block of the auxiliary blockchain; storing, in the seconddata block of the auxiliary blockchain, an identifier of the secondexternal storage location; appending, to the second data block of theauxiliary blockchain, a reference to the first data block of theauxiliary blockchain; and broadcasting the newly created data block ofthe auxiliary blockchain to the plurality of blockchain nodes.
 2. Themethod of claim 1, further comprising: performing a second intraoralscan of the oral cavity; identifying a second digital representation ofdental anatomy associated with the dentition; appending to the currentdata block of the main blockchain, a second data item of the seconddigital representation of digital anatomy; appending to the current datablock of the main blockchain, a reference to a preceding data block ofthe main blockchain; and broadcasting the current data block of the mainblockchain to a plurality of blockchain nodes.
 3. The method of claim 1,further comprising: providing instructions to manage a treatment planusing the first digital representation of dental anatomy.
 4. The methodof claim 3, further comprising: providing instructions to compare thefirst digital representation of dental anatomy and a second digitalrepresentation of dental anatomy.
 5. A method comprising: receiving, bya computer system, a reference to a digital representation of medicalanatomy of a patient, the digital representation of medical anatomydepicting an anatomical portion of the patient, wherein the digitalrepresentation of medical anatomy is encrypted using a secretcryptographic key; identifying an auxiliary blockchain having a firstplurality of cryptographically linked data blocks; identifying a mainblockchain having second plurality of cryptographically linked datablocks; adding the reference to the digital representation of medicalanatomy to a first data block of the first plurality ofcryptographically linked data blocks of the auxiliary blockchain; addingan identifier to a second data block of the second plurality ofcryptographically linked data blocks of the main blockchain, theidentifier identifying a first data block of the auxiliary blockchain;adding the secret cryptographic key to the second data block of thesecond plurality of cryptographically linked data blocks of the mainblockchain; sharing the second data block of the main blockchain with afirst plurality of blockchain nodes, wherein the first plurality ofblockchain nodes have received a third data block of the secondplurality of cryptographically linked data blocks of the main blockchainand the third data block of the main blockchain is cryptographicallylinked to the second data block of the main blockchain; receiving anotification of migration of the encrypted first digital representationof dental anatomy to a new external storage location; creating a seconddata block of the auxiliary blockchain; storing, in the second datablock of the auxiliary blockchain, an identifier of the new externalstorage location; appending, to the second data block of the auxiliaryblockchain, a reference to the first data block of the auxiliaryblockchain; and broadcasting the newly created data block of theauxiliary blockchain to the plurality of blockchain nodes.
 6. The methodof claim 5, further comprising sharing the third data block of the mainblockchain with the first plurality of blockchain nodes before sharingthe second data block of the main blockchain with the first plurality ofblockchain nodes.
 7. The method of claim 5, further comprising:receiving medical management data for a treatment plan for the patient,the medical management data associated with the digital representationof medical anatomy; and adding the medical management data to the seconddata block of the main blockchain.
 8. The method of claim 7, furthercomprising providing management instructions to manage the treatmentplan based on the medical management data.
 9. The method of claim 8,wherein the management instructions comprise one or more of diagnosticinstructions to diagnose a medical condition associated with thetreatment plan, treatment management instructions to manage at least aportion of the treatment plan for the patient, arbitrage manageinstructions to manage an arbitrage claim for the treatment plan,medical device management instructions to manage one or more medicaldevices implementing the treatment plan, and drug delivery instructionsto manage delivery of a drug implemented by the treatment plan.
 10. Themethod of claim 5, wherein the digital representation of medical anatomycomprises an image of the anatomical portion, the image is stored on anetworked location, and the reference comprises a hyperlink to thenetworked location.
 11. The method of claim 5, wherein the digitalrepresentation of medical anatomy comprises a two-dimensional (2D) orthree-dimensional (3D) scan stored on a networked location, and thereference comprises a hyperlink to the networked location.
 12. Themethod of claim 5, wherein the digital representation of medical anatomycomprises an intraoral scan stored on a networked location and theanatomical portion is associated with an intraoral cavity of thepatient.
 13. The method of claim 5, wherein the digital representationof medical anatomy is gathered as part of a treatment plan.
 14. Themethod of claim 5, further comprising: sharing the first data block ofthe auxiliary blockchain with a second plurality of blockchain nodes,and the second plurality of blockchain nodes have received a fourth datablock of the first plurality of cryptographically linked data blocks ofthe auxiliary blockchain and the fourth data block of the auxiliaryblockchain is cryptographically linked to the first data block of theauxiliary blockchain.
 15. The method of claim 14, further comprisingsharing the fourth data block of the auxiliary blockchain with thesecond plurality of blockchain nodes before sharing the first data blockof the auxiliary blockchain.
 16. The method of claim 15, wherein thesecond plurality of blockchain nodes are distinct from the firstplurality of blockchain nodes.
 17. The method of claim 5, wherein one ormore of the main blockchain and the auxiliary blockchain implements adistributed ledger.
 18. A method comprising: receiving, by a computersystem, a hyperlink to an intraoral scan depicting a dentition of apatient, wherein the intraoral scan is encrypted using a secretcryptographic key; identifying an auxiliary blockchain having a firstplurality of cryptographically linked data blocks; identifying a mainblockchain having second plurality of cryptographically linked datablocks; adding the hyperlink to the intraoral scan to a first data blockof the first plurality of cryptographically linked data blocks of theauxiliary blockchain; adding an identifier to a second data block of thesecond plurality of cryptographically linked data blocks of the mainblockchain, the identifier identifying a first data block of theauxiliary blockchain; adding the secret cryptographic key to the seconddata block of the second plurality of cryptographically linked datablocks of the main blockchain; sharing the second data block of the mainblockchain with a first plurality of blockchain nodes, wherein the firstplurality of blockchain nodes have received a third data block of thesecond plurality of cryptographically linked data blocks of the mainblockchain and the third data block of the main blockchain iscryptographically linked to the second data block of the mainblockchain; receiving a notification of migration of the encrypted firstdigital representation of dental anatomy to a new external storagelocation; creating a second data block of the auxiliary blockchain;storing, in the second data block of the auxiliary blockchain, anidentifier of the new external storage location; appending, to thesecond data block of the auxiliary blockchain, a reference to the firstdata block of the auxiliary blockchain; and broadcasting the newlycreated data block of the auxiliary blockchain to the plurality ofblockchain nodes.
 19. The method of claim 18, further comprising:receiving medical management data for a treatment plan for the patient,the medical management data associated with the intraoral scan; andadding the medical management data to the second data block of the mainblockchain.
 20. The method of claim 19, further comprising providingmanagement instructions to manage the treatment plan based on themedical management data.